"The probability is that we need not take the so-called ‘nature miracles’ as historical.” (Jesus the Christ, p. 90-91)

Again,

"We must assume therefore that we are faced not with historical details but with stylistic devices intended to attract the attention and raise excitement in the minds of those listening….” (Jesus the Christ, p. 127)

All of which, of course, is brazenly at odds with Catholic teaching. For example, in the documents of Vatican II we find this:

“Holy Mother Church has firmly and with absolute constancy held, and continues to hold, that the four Gospels just named, whose historical character the Church unhesitatingly asserts, faithfully hand on what Jesus Christ, while living among men, really did and taught for their eternal salvation until the day He was taken up into heaven.” (Dei Verbum, 19)

Which means that Kasper is more beholden to the currently ascendant and fashionable Biblical hermeneutics of the self-congratulatory post-Enlightenment establishment emanating from the erstwhile fevered swamplands of liberal Protestant "higher criticism" than he is with the teaching authority of his own Church. Should anyone be surprised?